Other universities achieving the highest Gold award are Cambridge University, Imperial College London, and Birmingham University.
Lincolnshire's two universities are among only 26% of higher education providers from across the whole of the United Kingdom to be awarded a Gold rating.
But Coventry University, a newer institution which scored a gold, said the TEF showed that universities can not rely on their "historic reputation".
In order to be considered for a TEF rating, higher education providers have to meet demanding national quality requirements.
The group said it does not believe the TEF measures "absolute quality" and that would-be students need clear guidance about what the results mean and how they should be used.
The Teaching Excellence Framework (TEF) has awarded gold awards to over a quarter of the 295 universities, colleges and alternative providers of higher education that voluntarily took part in the TEF.
43 universities received a gold rating (32%), with 67 receiving silver (50%), and 25 getting the lowest rating, bronze (18%). "We are particularly pleased that assessors highlighted our institutional culture that facilitates, recognises and rewards excellence in teaching and we will use this outcome as a benchmark for future development".
They were assessed on a range of measures, including teaching quality, student satisfaction, drop-out rates and whether students go on to employment or further study after graduating.
The university's principal, Professor Ferdinand von Prondzynski responded to the news by declaring the award meant RGU was now among the United Kingdom "elite".
In response to the rating, Vice Chancellor Mary Stuart said the university is "delighted" by the decision.
"Every single one of them has contributed to this institutional award, and I want to thank them all".
Prof Prondzynski, who has been a significant force in the drive for excellence, added that the award was evidence of the staff's "exceptional dedication" to their work in the education sector.
Professor Mohammad Dastbaz, deputy vice-chancellor at the University of Suffolk, said: "The University of Suffolk has been awarded Bronze by the Teaching Excellence Framework (TEF) panel, which is valid for three years".
"UK universities must seriously consider the impact of the ratings on their global student recruitment", counselled Paul Raybould, Hobsons' marketing director.
Sally Hunt, general secretary of the University and College Union, said there are concerns about how global students will view the results.
"The fear is that students, beyond the United Kingdom in particular, will use these results as the basis for deciding which United Kingdom university to attend, which could damage some institutions".